Compositions for use in the manufacture of light-sensitive photographic materials



COMPOSITIONS FOR USE IN THE MANUFAC- TURE OF LIGHT-SENSITIVE PHOTOGRAPHIC Fred Dawson, Clifford Ronald ]1lsley,'Jol1n Lewis Moi]- liet, and Hans Werner Gustav Ziegler, Blackley, Manchester, England, assignors to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain No Drawing. Application November 7, 1955 Serial No. 545,556

13 Claims. (CI. 96-97) This invention relates to new compositions for use in the manufacture of light-sensitive photographic materials.

In the conventional processes for the coating of a lightsensitive gelatino-silver halide emulsion layer on a film base or on paper, difiiculties arise due to the physical properties of the emulsion and, because of the necessity for drying the gelatin emulsions slowly, large volumes of dust-free air are required for the drying operation and the drying equipment occupies much space.

It has been proposed to convert differently sensitized emulsions into small grains by emulsification in a liquid immiscible therewith, for example tetrahydronaphthalene or xylene and to re-emulsify the particles, after Weak tanning, in gelatin or collodion or other colloid solutions permeable to the developer.

We have now found that by emulsifying gelatino-silver halide emulsions in solutions of certain polymers, compositions are obtained which have superior properties to normal gelatino-silver halide emulsions in that they can be more readily coated to give layers of uniform thickness and in that the drying of the emulsion layers can be effected very much more rapidly. It has been also found that highly desirable results can be obtained using silver halide emulsions in which some or all of the gelatine is replaced by a \gelatine substitute.

According to the invention, therefore, we provide a new composition for use in the manufacture of light-sensitive photographic materials which comprises an emulsion containing, as the dispersed phase, a light-sensitive aqueous silver halide emulsion, and as the continuous phase a solution of a water-insoluble, water-permeable polymer in a water-immiscible organic solvent.

The new compositions may be made by adding the aqueous gelatinoor gelatine substitute-silver halide emulsion after the addition of a hardening agent if such is desired, to the solution of the water-insoluble, water-perme able polymer and stirring the mixture. The emulsion so obtained may be homogenized in any known homogenizer.

For the dispersed phase of our new compositions, there may be used normal black and white gelatinoor gelatine substitute-silver halide emulsions which may contain sensitizing dyestuifs or other adjuvants', or if desired there may be used gelatinoor gelatine substitute-silver halide emulsions of suitable spectral sensitivity for use in color photography, by development in a developer solution containing color-former or the emulsions themselves may contain color formers, for example color formers of the nondifiusing type, which give rise to colored images on exposure and development with a chromogenic developer and preferably those with a low solubility in the water-immiscible solvent.

If desired, the dispersed phase may comprise a mixture of particles of differently sensitized silver halide emulsions containing color formers, some of which may be colored or otherwise provided with means to protect the silver halide from light of particular wavelengths. For example,

there may be used a mixture of particles of a blue sensitive emulsion containing a yellow color former,- a green-sensi- United States Patent terephthalate containing from 20% to of Patented July 7, 1959 2 tive emulsion which is not significantly sensitive to blue light (for example a green-sensitised gelatino-silver chloride emulsion), and a magenta color former and a redsensitive emulsion which is not significantly sensitive to blue light (for example ared-sensitised gelatino-silver chloride emulsion) and a cyan color former.

Such a mixed packet emulsion may conveniently be made by separately treating with hardening agents three differently-sensitised silver halide emulsions each containing the appropriate color formers, separately emulsifying the silver halide emulsions in solutions of the water-insoluble, water-permeable polymer in the same or different water immiscible solvents and simply mixing together the emulsions so obtained. As suitable hardening agents there may be used for example, 'aldehydes such as formaldehyde or glyoxal, or chromium compounds such as chromealum. The water-insoluble, water-permeable polymer used in the continuous phase of our composition must be capable of forming a film when it is coated as a solution on a substrate and the solvent is evaporated ofi, and the film thus obtained must be permeable to the developer and the other solutions to be used in processing the photographic materials.

If desired, the processing solutions may contain watersoluble organic solvents for example ethanol, acetone or fl-ethoxyethanol to assist penetration of the solution into the film. The water-insoluble, water-permeable polymer must not be appreciably dissolved or decomposed by the developer or other solutions to be used in processing."

The polymers which may be used in the process of our invention include natural polymeric materials and also artificial polymeric materials formed by addition polymerization or by polycondensation. Copolymers, block copolymers and mixed polymers may be used if desired. As examples of the classes of polymers from which waterinsoluble, water-permeable polymers may be selected there may be mentioned: Polymers formed from olefinic monomers, for example, polyacrylamide or acrylate polymers such as a polyalkyl methacrylate. Particularly useful are copolymers of methyl methacrylate and methacrylic acid polymerized together in the ratios, by weight, of,-for example, 70/30, 60/40, 50/ 50. Other types of copolymers of interest are those obtained by polymerizing mixtures of butyl methacrylate/methyl methacrylate/methacrylic acid in the ratios of 10/30/60 or 20/40/40, ethoxyethyl methacrylate/methyl methacrylate/methacrylicacid in the ratios of 20/40/40 or 10/40/50, nonyl methacrylate/methyl methacrylate/methacrylic acid in the ratio of 20/30/50, styrene/methyl methacrylate/methacrylic acid in the ratio of 20/30/50 and styrene/ethoxyethyl methacrylate/methacrylic acid in the ratio of 20/ 30/ 50.

Polyamides and polythioamides for example 'N-methoxymethyl-polyhexamethyleneadipamide and polymers prepared from l:2-bis( 3-aminoethoxy)ethane andisosebacic acid or from 1:2-bis(' -aminopropoxy)ethane and hexamethylenediamine or from N-isobutylhexamethylenediamine and adipic acid or from 1:2(B-aminoethoxy) ethane and isophthalic acid orfrom hexamethylenediamine and diglycollic acid. Also copolymers prepared from p:p' diaminodicyclohexylmethane and adipic acid with caprolactam and with p:p"-diaminodicyclohexylmethane and. sebacic acid, or from 1:2-bis(,8-aminoj ethoxy)ethane and isosebacic acid (or adipic acid) with hexamethylenediamine and adipic acid, or from hexamethylenediamine and adipic acid with hexamethylenediamine and sebacic acid and with caprolactam. 1 Polyesters for example diethyleneglycol terephthalate and copolymers for example copolymers obtained by polymerising mixtures of ethylene adipate and ethylene e hyl n adipate, and also polyester-amides...

'atives-for example cellulose tripropionate, cellulose triacetate, de-acetylated chitin, and 'methylamino-cellulose.

Natural and synthetic proteins such as zein and'zein derivatives such as piperidyl zein.

V Lignins.

Polyanhydrides. Polyamines. Poly-quaternary ammonium salts. Poly-a zomethines. Poly-sulphides, -sulphones and -sulphonium salts. Polyethers such as polydimethoxy-methyloxabutane. Poly-hotels, thioketals, wactalsand -thioacetals. Poly-ureas, -thioureas and -guanidines. Polyurethanes, -thiour'eth'anes, '-thiolurethanes and -dithiourethanes.

Polyamidines, -imidoethers and -thiimidoethers. The water-insoluble polymers from the above classes which form on'substrates, layers permeable to photographic processing solutions and which are suitable for mom the process of our invention,'are in general those which contain hydrophylic groups for example hydroxyl-,

ester-, carboxyl-, acyl-, ether-, nitrileor amide-groups, but other water-insoluble polymers which form permeable layers on substrates may be used if desired. The permeability of the layers can be increased if desired by adding one or more water-sensitive plasticizers to the polymers.

The permeability of the wat'er-insoluble polymer layer to photographic processing solutions can be readily'determined by experimental trials with such solutions to determine whether the solutions difiuse through a thin layer ofthe polymer and process a photographic film which has been exposed to light after a thin layer of the polymer has been coated on to it. A quantitative assessment of the permeability to an aqueous solution of a .sodium salt of an organic acid, which can be regarded as a measure of the permeability to photographic processing solutions, can be carried out as follows: A layer of transparent water-retaining material (for example,

. gelatine gel, agar gel, or regenerated cellulose) of thickness A centimetres, is coated'with a thin layer of the water-insoluble polymer of thickness B centimetres and samples of the compositefilm thus formed are arranged with the water-insoluble polymer side of the film in contact with a large volume of an aqueous solution of sodium that on standard films made up by coupling to form the azo dyestuft on films containing known amounts of sodium 2-naphthol-3-sulphonate, the quantities of sodium 2-naphthol-3-sulphonate contained in the composite film after definite intervals of time are determined, and also the quantity in the composite film when this is in equilibrium with the aqueous solution' of sodium 2-naphthol- 3-suIphonate. The permeability (P) in square centimetres per second, whichis' the quotient of the difiusion 'coeificient of sodium 2-naphthol-3-sulphonate in the film 'divided by the partition coefficient of sodium 2-naphthol- B-sulphonate between the aqueous solution and the film, is then calculated from the expression where F is the ratio of the weight of sodium Z-naphthol- 3-sulphonate per unit-area -in'the composite-film at. time "hydrolysed cellulose acetate.

4 T seconds to the weight of sodium 2-naphthol-3-sulphonate per unit area of film in equilibrium with the aqueous solution.

Water-insoluble polymers with permeability for sodium 2-naphthol-3-sulphonate in equilibrium with its aqueous solution determined as hereinbefore defined, greater than -l0'- 'square centimetres per second are suitable for use in the compositions and processes of the present invention.

By water-immiscible solvent, we mean a solvent for the polymer which at the temperature at which the composition is made orusedwill not mix completely to form a single liquid phase, with the quantityof water contained in the aqueous silver halide emulsion and will not dissolve in the aqueous silver halide emulsion to a sufficient extent to precipitate any'g'elatine or gelatine substitute from solution. Suitable solvents are, for example, xylene, tetrahydronaphthal'ene, benzene, toluene, carbon tetrachloride, monochlorobenzene, or ethylene dichloride.

Mixtures of the solvents can be used and it has been found that the permeability of the photographic layer to photographic processing solutions can be improved by using a mixture of a'low boiling solvent in which the polymer is-very soluble and a higher boiling solvent in which the polymer is sparingly soluble, so that when the solvents are evaporated oil from the layer of the light sensitive composition on the substrate, a porous layer of the water-insoluble polymer containing gelatinoor gelatine s'ubstitute silver halide emulsion is formed.

By gelatine substitutes we mean substances which can replace gelatine in the formation of silver halide dis persions. The substances'must be soluble or dispersible in water under the conditions of emulsion preparation, and when coated as films containing dispersed silver halide particles, they must be permeable to cold water and aqueous processing solutions, and, either alone or in conjunction with one or more dispersing agents, they must be capable of maintaining silver halide in a fine state of dispersion in aqueous media. They' must be substantially insoluble in the water-immiscible solvent in which the water-insoluble polymer of the continuous phase is dissolved.

As examples of the many classes of known gelatine substitutes, that is to say substances which are known from the literature or used 'in practice to replace the gelatine in gelatino-silver halide emulsions, there may be mentioned:

Water-soluble or water-dispersible polyamides such as salts of N-carboxyalkoxymethyl polyamides and polyamide ethers. As a particular compound of this class there may be mentioned the potassium salt of N-carboxymethoxymethyl polyhexamethylene sebacate (British patent specification No. 619,553).

Water-soluble or water-dispersible hydrolysed or partially hydrolysed vinyl ester polymers and interpolymers and acetals thereof. These in general are polyvinyl esters and acetals with sufficient intralinear CH CH(OH)-- groups to make them hydrophilic. Polyvinyl acetates hydrolysed to the extent of from 80% to 100% are very suitable. Suitable polyvinyl acetals include polyvinyl propionaldehyde acetal containing from. 50% to 60% of hydroxyl groups calculated as vinyl alcohol and polyvinyl butyraldehyde containing from to of hydroxyl groups calculated as vinyl alcohol (British patent specification No. 543,854).

Water-permeable cellulose derivatives such as partially The preferred degreeof hydrolysis is such that the acetate group content is from 19% to 24%. This provides a water-permeable but not water-soluble material (British patent specification No. 479,239).

- Especially desirable are gelatine substitutes which are free from strongly ionizing groups since swelling is minilmized when thefinal photographic elements are processed so that the processed photographic layers are much stfonger mechanically.

I The new compositions of our invention have physical properties similar to those of spirit printing inks or lacquers and their viscosity can be controlled over a wide range by adjusting the relative proportions of the ingredients. As a consequence of this, the compositions can be coated onto substrates by high speed coating methods which cannot be used with, for example, conventional gelatine-silver halide emulsions, which froth readily and havea watery consistency at temperatures only "slightly above the gelling point. Layers of the new compositions can be dried much more rapidly than the conventional emulsion layers. V According to a further feature of our invention, we provide a process for the manufacture of light-sensitive photographic materials which comprises coating a new composition, as hereinbefore defined, onto a substrate and evaporating off the water-immiscible solvent and if desired, some or all of the water from the composition.

In general suificient water from the composition is evaporated off so that the particles of silver halide emulsion in the light-sensitive photographic layer so obtained contain about to by weight of water, but the final water content can be higher or lower than 10% to 15% if desired.

' The aqueous silver halide emulsions used for forming the new compositions of our invention usually contain more water than is required in the silver halide emulsion particles of the final light-sensitive layer and we prefer to removeat-least part of the surplus water, for example by heating the composition (under reduced pressure if desired), preferably with agitation or by heating the composition with a dehydrating agent, before coating the composition on the substrates.

The coating onto the substrate can be carried out, for example, by application on a fiat bed printing press of the kind used for applying printing inks to paper, by spreading by means of a doctor knife, by dip-coating, offset printing, or by application by rollers. Roller-coating machines operating on the reverse-roller principle, in which the periphery of the applicator travels in a direction opposite to that of the substrate being coated, are particularly suitable.

If desired, the same substrate may be coated with compositions which contain difierently sensitised gelatinoor gelatine substitute-silver halide emulsions together with color formers. For example, there may be coated onto the substrate (1) a composition in which the dispersed phase is a red sensitive emulsion containing a cyan color former, (2) a composition in which the dispersed phase is 'a green sensitive emulsion containing a magenta color former, (3) a dischargeable yellow filter layer (if the emulsions of the first two layers are sensitiveto blue light) and (4) a composition in which the dispersed phase is a blue sensitive emulsion containing a yellow color former.v Alternatively, the various differently sensitized emulsions containing the color formers may be dispersed in the same composition before coating on the substrate. If desired, the various emulsions may be free from color formers and the photographic material may then be used in color photographic processes which involve selective exposure and/ or development with color developers containing color formers.

As a suitable substrate there may be used, for example,- If desired, the substrate may be treated before applying the composition,-

a transparent film base or paper.

baryta or titanium dioxide in a solution of ethyl cellulose or in a solution of other film-forming material.

7 In the' photographic material obtained by the process of our invention, the sensitive layer superimposed on-the' substrate is a layer of the water-insoluble polymer, e.g. cellulose ether, containing particles of light-sensitive gelatine or gelatino-substitute silver halide emulsion and according to a further feature of our invention, we provide a light-sensitive photographic material which comprises a substrate and at least one superimposed layer of a water-insoluble polymer which is water-permeable, i.e. permeable to photographic processing solutions and contains dispersed as a discontinuous phase, a light-sensitive silver halide emulsion.

The invention is illustrated but not limited by the following examples inwhich the parts are by weight.

Example 1 500 parts of a silver chloro-iodo-bromide emulsion suitable for photographic paper and containing 9.6% gelatin, 4.5% of silver bromide, 0.1% of silver iodide and 0.04% of silver chloride, are stirred at 45 C., and 10 parts of a 0.05% solution in methanol of the red sensitizing dyestuif Rr 1953, described in B.I.O.S. Final Report No. 1355, Item No. 22, page 87, are added. The mix ture is stirred for 15 minutes and parts of a 5% solu-' tion of the sodium salt of 1-hydroxy-4-sulpho Z-naphthoyl-octadecylamide in a mixture of 7 parts of water and 1 part of methanol are added. The pH of the mixture is adjusted to 7.0 by the addition of acetic acid, and

the mixture is then gradually added, with vigorous stir? ring, to 800 parts of a xylene solution at 45 C., con

taining 63 parts of ethyl cellulose (having an ethoxyl content of 46.8% to 48.5%). The resulting emulsion, which is immiscible with water but miscible with Xylene, is then passed twice through a valve homogenizer. i

The emulsion is applied to the surface of a paper base,

carried on a "tensioned moving rubber conveyor and spread into a uniform thin layer by passing the paper on the conveyor under a doctor knife. The emulsion layeris then dried at 40v C. The resulting photographic paper gives a characteristic cyan image when exposed to red. or blue light and developed with a chromogenic developer,

for example NzN-diethyl-p-phenylene diamine.

Instead of applying to the paper base the emulsion con taining all the water, some of the water can be removed from the water-immiscible, xylene-miscible emulsion before it is applied to the paper base, by stirring the emulsion immediately after homogenization, at a temperature.

of 50 C., and a pressure of mm. of mercury, and replacing the xylene which distils 01f. The resulting dispersion can be applied by the method described or by any conventional printing method. It dries very rapidly in warm air (for example in air at 40 C.), so that the coating step can be carried out -very rapidly.

Example 2 used in Example 1, there are used 15 parts of a 0.05 solution in methanol of the green sensitizing dyestufi Rr 340 described in B.I.O.S.' Final Report No. 1355, Item No. 22, page 86, and 100 parts of a 5% aqueous solution of the sodium salt of' 1-(4- phenoxy-3'-sulphophenyl)-3-heptadecyl-5-pyrazolone. I a

The resulting dispersion can be applied to a paper base as described in Example 1, and dried, when a photosensitive layer is obtained, which is sensitive to green or blue light, and yields magenta images when exposed to green or blue light and developed in a chromogenicdeveloper V l for example NzN-diethyl-p-phenylene diamine p Example 3 100 parts ofagelatino-silver halide emulsion at 40 C. containing 2.5 7%. of silver, 1.85% of bromine as bromide, 0.03% of iodine as iodide and 8.7% of gelatineare added to 200 parts of a well-stirred solution of ethyl cellulose in carbon tetrachloride at 40 C. The mixture is passed through a colloid mill and obtained in the formof a mobile liquid emulsion With the particles of the dispersed phase having a diameter of 6-10 microns. A layerofthe emulsion is applied to a paper base by the engraved roller coating method, and the layer is then dried.

The photosensitive material thus obtained is exposed to :the light transmittedby a photographic negative and developed with a.metal/hydroquinone developing solution containing of methanol, fixed with sodium thiosulphate solution containing 10% methanol, rinsed inwater and dried. A black and white image is obtained. The speed of the photosensitive material is equal tovthat of the original gelatino-silver halide emulsion used.

In place of the metol/hydroquinone developer used in the above example, any other conventional black and white developer may be used and in place of the 10% methanol in the developing and fixing solutions, 10% of ethanol, butanol or acetone may be used.

Example 4 100 parts of a gelatino-silver halide emulsion of the kind used in Example 3 is stirred at 40 C. and 2 parts of a 0.05% solution in methanol of the red-sensitizing dyestuffRr 1953 are added. The mixture is stirred for 20 minutes at 40 C., and 20 parts of a 5% aqueous solution of the sodium salt of 2-(1-hydroXy-2-naphthoylamino) 1 (N-methyl N octadecylamino) benzene-4=sulphonic acid are added. The mixture so obtained is added to 200 parts of a well-stirred 5% solution of ethyl cellulose in tetrahydronaphthalene at 40 C. The mixture is passed through a homogenizer to form a mobile liquid emulsion, the particles of the dispersed phase of which have a diameter of between 2 and 10 microns. The emulsion is coated onto paper as a uniform thin layer by the ofiset printing process and the layer is then dried.

The photosensitive paper so obtained is exposed to light, developed with a color forming developer, bleached and fixed when a cyan colored image is obtained. The photographic speed of the paper is equal to that of the original gelatino-silver halide emulsion.

Example 5 A blue sensitive emulsion (Emulsion A) is made up as follows:

20 parts of 5% methanolic solution of the yellow color former, 3 -(p-anisoyl acetylamino) 4 (N methyl- N-octadecylamino) -benzoic acid are added to a gelatinosilver halide emulsion containing 2.3% of silver, 1.85% of bromine (as bromide), 0.03% ofiodi'ne (as iodide) and 8.7% of gelatine. The solution stirred at 40 C., and 7 parts of a 10% aqueous solution of chrome alum are added. The solution is stirred for 1 minute and then added to 200 parts of a well-stirred 5% solution of-ethyl cellulose in benzene. The mixture is passed through a colloid mill to .form a mobile liquid emulsion, the particles of the dispersed phase of which have a diameter.

of about6 microns.

A green sensitive emulsion (Emulsion B) is made up as follows:

' 2 parts of a 0.05% solution in methanol of the green sensitizing dyestuii Rr 340 are added to 100 partsof agelatino-silver halide emulsion which. is relatively insensitive to blue light and contains 1.59% ofsilver, 0.625% of chlorine,(as chloride), 0.029% of-bromine (as bromide) and 10.6% of gelatine. The mixture is stirred for 20 minutes and 20 parts of a 5% aqueous 8 solution of the sodium salt of the magenta color, former. obtained by acylating 4-omega-cyanoacetoaniline with octadecenylsuccinic anhydride, are added. The mixture.

is stirred at 40 C. and 3 parts of a 10% aqueous solution of chrome alum are added. The mixture so obtained is stirred for 1 minute and then added to 200 parts of a well-stirred solution of ethyl cellulose inbenzene. The mixture is passed through a colloid mill to form a mobile liquid emulsion, the particles of. the dispersed phase of which haye a diameter of about 6 microns.

A red sensitive emulsion (Emulsion C) is made up as follows:

2 parts of a 0.05% methanolic solution of the red sensitizing dyestulf Rr 1953 are added to parts of the gelatino-silver halide emulsion used for making Emrulsion B. The mixture is stirred for 30 minutes and 20 parts of a 5% aqueous solution of the sodium salt of the cyan color former, 2-(l'-hydroxy-2' naphthoylamino)-1-(N-methyl-N-octodecylamino) benzene 4 sulphonic acid, are added. The mixture is stirred at 40 C. and 3 parts of a 10% aqueous solution of chrome alum are added; The mixture so obtained is stirred for 1 minute and then added to 200 parts of a 5% solution of ethyl cellulose in benzene. The mixture is passed through a colloid mill to form a mobile liquid dispersion, the particles of the dispersed phase of which have a diameter of about 6 microns.

Equal parts of Emulsions A, B and C are mixed together and the mixture is coated onto a paper base to form a thin uniform layer. The coated paper is dried and the photosensitive paper thus obtained is exposed to the light transmitted by a color photographic negative. The exposed paper is developed with an aqueous solution of NzN-diethyl-p -phenylene diamine containing 10% of fi-ethoxyethanol, Washed, fixed in an aqueous solution of sodium :thiosulphate containing 10% of fi-ethoxyeth anol, Washed, treated with an aqueous solution of potassium ferricyanide containing 10% of fl-ethoxyethanolto bleach the developed silver again treated with an aqueous solution of sodium thiosulphate containing 10% of Beth oxyethanol and finally washed and dried.

A three colored image is obtained in which each colored image is substantially independent of the intensities of the other two colored images.

Example 6 An aqueous light-sensitive photographic emulsion is prepared by dissolving parts of polyvinyl alcohol in 1600 parts of distilled water at 75 C. 76 parts of potassium bromide and 3 parts of potassium iodide are then added and the mixture is stirred until the solid has dissolved. 100 parts of silver nitrate are dissolved in 250 parts of distilled water, wfficient 30% aqueous ammonia solution is added to re-dissolve the precipitate of silver oxide, first formed, and the temperature is then adjusted to 70 C. This ammoniacal silver nitrate solution is poured during 10 seconds into the well-stirred polyvinyl alcohol-potassium halide solution. Stirring is continued for 10 minutes at 70 C., and the mixture is then allowed to cool.

Dilute sulphuric acid is added to parts of the light: sensitive photographic emulsion so, obtained to adjust the pH to between 5.8 and 6.2, and the lvolume is then adjusted to 200 parts by the addition of water. The emulsion is added to 200 parts of a vigorously stirred 2% benzene solution of ethyl cellulose (which has an ethoxyl content of between 46.8% and 48.5%). The resultant coarse water-in-oil emulsion is homogenized twice through a colloid mill.

. sulphate and concentrated by vacuum distillation. at 30v C., down to one-third of its original weight.

The composition so obtained is applied to the surface of a paper carried in a tensioned moving rubber conveyor and the composition is spread into a uniform thin layer by passing the paper in the conveyor under a doctor knife. The emulsion layer is then 'dried at- 20 C.-40 C. .The resulting photographic paper gives ablackand white image when exposed to light and developed with ametol/hydroquinone developer;

Example 7 100 parts of a gelatino-silver chloride-iodide emulsion suitable for the preparation of photographic printingpaper and containing 2.2% of silver and10% of gelatine,

the; ratio of silver chloride to silver iodide being 169:1

are stirred at 40 C., until a liquid emulsion is formed and this liquid is then added to 100 parts of a solution of the polyester derived from diethylene glycol terephthal-ate in chloroform which is stirred vigorously at 40 C. The water-in-oil type of emulsion thus obtained is passed twice through a colloid mill, when a fine water-in-oil type of emulsion is obtained.v

.The emulsion so obtained is applied to a paper base by means of a draw knife to form an emulsionlayer of: such thickness 'that it contains 2 grams of silver. per spare meter and the emulsion layer is dried. When' The permeability of the polyester is 4.1 centimeter /second, as determined by the process as hereinbefore defined.

Example 8 In place of the 100 parts of a 5% solution in chloroform of the polyester used in Example 7, there is used a mixture of 100 parts of a 5% solution of this polyester in a solvent consisting of equal parts of chloroform and butanol and 25 parts of a 10% solution of ethyl cellulose (having an ethoxy content of 46.8% to 48.5%) in the same solvent or alternatively there is used a mixture of 80 parts of a 5% solution of the same polyester in this solvent and 2 parts of a 10% solution of this ethyl cellulose in this solvent.

Example 9 500 parts of a gelatino-silver chloride emulsion conassess? taining 2.7% of silver and 10% of gelatiue are stirred and 4,000 parts of ethanol are added; The precipitated tained. ZQparts of this partially dehydrated emulsion and 40 parts of water are stirred at 40 C., until a fluid emulsion is obtained and 0.25 part of a 47% aqueous solution of formaldehyde is added. The mixture is stirred-for 2' minutes and then added to 100 parts of a 5% solution in a mixture of equal parts of chloroform and Qbutanol of-a copolymer of methyl methacrylate and methacrylate acid. The resulting water-in-oil typev of emulsion obtained is passed twice through a colloid mill, when a fine emulsion is obtained. The emulsion so obtained isqcoated onto a paper base and the emulsion layer so formed is dried. When the photosensitive material thus obtained is exposed, developed with a metol/ hydroquinone developer and fixed, a black and white image is obtained.

.10 I The copolymer used in the above example may be made up as follows:

1 part of a partially hydrolyzed polyvinyl acetate is added to 400 parts of Water and the mixture is stirred at C., during the addition of a solution of 38.7 parts of methacrylic acid, 30.0 parts of methyl methacrylate and 0.2 part of azo-bis-isobutyronitrile. The mixture is stirred at 85 C., for 2 hours and is filtered at 85 C. The residue is washed with hot water and then dried. The permeability of the polymer determined as hereinbefore defined is 2.6 X 10' centimeter second.

Example 0 20 parts of the partially dehydrated emulsion, preparedby ethanol precipitation as described in Example 9, and 50 parts of water are stirred together at 40 C., until a fluid emulsion is formed. 2.4 parts of a 0.02% solution in methanol of the sensitizing dyestuff 3-ethy1- 5- (3'-ethyl-2'-thiazolinylidene-ethylidene)-rhodanine are added and the mixture is stirred for 5 minutes. 0.25 part of a 47% aqueous solution of formaldehyde is then added to parts of a 5% solution of acopolymer of methyl methacrylate and methacrylic acid in a mixture of 3 parts of chloroform and 1 part of butanol which is stirred at 40 C. The emulsion so formed is passed twice through a colloid mill to give a fine, water-in-oil type, photosensitive emulsion which is coated onto a subs-tate and dried. When the photosensitive material isexposed, developed with a metol/hydroquinone developer and fixed, a black and white image is obtained.

In place of the '100 parts of the 5% solution of the copolymer in the mixture of chloroform and butanol used in this example, there may be used 100 parts of an 8% solution of the same copolymer of methyl methacryla'teand methacrylic acid in a mixture of equal parts of chloroform and butanol.

Example I] 100 parts of a gelatino-silver chloride emulsion containing 2.7%- of silver and 10% of gelatiue are stirred at 40 C., until a fluid emulsion is formed. The emulsion is added to 100 parts of a 5% solution of N-methoxymethylpolyhexamethylene adipamide in a mixture of equalparts of chloroform and butanol which is stirred vigorously at 40 C. The resulting emulsion is passed twice through a colloid mill to give a fine, water-in-oil type emulsion. This emulsion is coated as a layer of uniform thickness on a paper substrate and the layer is then dried. When the photosensitive paper so obtained is exposed to the light transmitted by a photographic negative and then developed with a metol/hydroquinone developer and fixed, a black and white image is obtained. The N-methoxymethylpolyhexamethylene adipamide used in the above example may be made as follows:

' 122 parts of methanol, 28.8 parts of water, 96 parts of paraformaldehyde, 0.13 part of 32% caustic soda solution and 100 parts of polylrexamethylene adipamide are heated to 139 C. in an autoclave. 900 parts of phosphoric acid are added and' the mixture is heated at 139v C. for a further 10 minutes. The solution is filtered and diluted with 1,200 parts of 'water and the precipitated solid is filtered off and dried. The permeability of the material, determined as hereinbefore defined, is 8.3 X 10- centimeter second.

Example 12 20 parts of the partially dehydrated emulsion prepared by ethanol precipitation as described in Example 9 and 40 parts of water are stirred at 40 C., until a fluid emulsion is obtained and 2.4 parts of a 0.02% solu tion in methanol of the sensitizing dyestuff used in Example 10 are added. The mixture is stirred for 5 minutes, 0.25 part of a 47% aqueous solution of formaldehyde is then added. This mixture is stirred for 2 minutes and added to a mixture of 100 parts of a 5% solution of N-methoxymethylpolyhexamethylene, adipamide in a mixture of equal parts of chloroform and butanol and 10 parts of a 10% solution of ethyl'cellulose (hav-. ing an ethoxyl content of 46.8% to 48.5%) in a mixture of equal parts of. chloroform and butanol. A similar photosensitive material is obtained.

In the above example the 10 parts of ethyl cellulosesolution can be omitted and the quantity of water used for making thesfiuid emulsion is then increased from 40 parts to 60 parts.

Example 13 In place of the 100 parts of a solution of N-methoxymethylene adipamide in a mixture of equal parts of chloroform and butanol used in Example 12, there are used 100 parts of a 5% solution in a mixture of benzene and butanol of the superpolyamide obtained -by condensing 1:2tbis-(fi-aminoethoxyyethane with isosebacic acid as described below.

The superpolyamide used in the above example may be prepared as follows:

5 parts of isosebacic acid and 7.5 parts of 1:2-bis- (fl-aminoethoxy)-ethane are heated together in an evacuated and sealed reaction vessel at 220 C., for 21 hours and the low molecular Weight polymer thus formed is heated under an atmosphere of nitrogen at atmospheric pressure and at 224 C., of 1 /2 hours.

Example 14 In place of the 100 parts of a 5% solution of N- methoxymethyl-polyhexamethylene adipamide in a mixture ofequal parts of chloroform and butanol used in Example 12, there are used 100 parts of a 5% solution in a mixture of butanol and chloroform of the superpolyamide obtained by condensing 1:2 bis-('y-amino propoxy)-ethane and hexamethylene diamine with adipic acid as follows:

8.8 parts of 1:2 bis-('y-aminopropoxy)-ethane, 7.3 parts, of adipic acid and 8.73 parts of the salt formed from hexamethylene diamine and adipic acid-are heated together in an evacuated'and sealed tube at 220' C;, for 2 hours, and'the low molecular weight product thus formed is heated under an atmosphere of'nitrogen at atmospheric pressure and at 260 (3., for 2 /2 hours; The permeability of this superpolyamide determined by the process as hereinbefore defined is 9.28 centimeter second.

Example -15 In place of the 100 parts of a 5% solution of N- methoxymethylpolyhexamethylene adipamide in a mixture of equalparts of chloroform and butanol used in Example 12, there maybe used 100' parts of a 3% solution in a mixture of xylene and chloroform of a copo-lymer'of nonyl methacrylate and methacrylamide, prepared as follows:

5 parts of a 5% aqueous solution ofgum tragacanth' are added to 400 parts of water and the-mixture is stirred at 85 C., during the simultaneous'addition of a solution of 17 parts of methacrylamide in-l70 parts of Water, and. a mixture of'5 parts ofazo-bis-isobutyronitrile and 42.4 parts .of nonyl methacrylate, during 2 hours. The. mixture is then stirredat 85 C.', for 2 hours and filtered at 85 C. The residue is then washed With-hot water and dried. The permeability of this copolymer determined by the process as hereinbefore definedis 1.7 x 10- centimeter second.

This application is a continuation-in-part of Serial No.- 360,602, filed June 9, 1953.

We claim:

manufacture of light-sensitive photographic materialswhich comprises preparing a solution of a water-insoluble, water-permeable cellulose ether in a water-immiscible .or-

ganic. solvent and. thereafter emulsifying. an aqueous.

silver halide emulsion in said solution.

2. A process for making a composition for use in the manufacture, of light-sensitive photographic mate amino developer to form adye, separately emulsifying said silver halide emulsions in dilferent portions of said solution and mixing together the emulsions-thus obtained.

3. A process for the manufacture of light-sensitivephotographic materials which comprises coating a base with an emulsion including (1) a light-sensitive aqueous silver halide emulsion as the discontinuous phase and (2) a solution of a water-insoluble, water-permeable cellulose ether. in a water-immiscible organic solvent as the corn tinuous phase and thereafter evaporating off the. waterimmiscible organic solvent.

4. A new composition .for use .inathe manufacture of light-sensitive photographic materials which comprises an emulsion-containing, as the discontinuous phase,.a light-sensitive, aqueous gelatino-silver halide emulsion, and as thecontinuous phase a solution of a water-insoluble, water-permeable cellulose ether in a water-immiscible organic solvent.

5. A new composition according to claim 4 wherein the discontinuous phase. is a black and White gelatinoe silver'halideemulsion. Y v 6.. A new'compositionaccording to claim 4 wherein the, discontinuous phase is a gelatinorsilver halide emulsion containinga color former capable of coupling with the oxidation product of a primary aromaticamino; developer to form a dye.

7. A new composition according to claim 4 wherein the. discontinuous phase comprises a mixture of particles of dilferently sensitized gelatiuo-silver halide, emulsions containingcolor formers capable of couplingwith the;

11. The composition-of claim'4, wherein the solvent is toluene.

' 1. A process formaking a compositionforuse in the 12. The composition of claim 4, wherein the solvent is tetrahydronaphthalene.

' 13. The composition of claim 4, wherein the solvent is carbon tetrachloride.

References Cited in the file of this-patent UNITED STATES PATENTS wherein the solvent wherein the solvent 

4. A NEW COMPOSITION FOR USE IN THE MANUFACTURE OF LIGHT-SENSITIVE PHOTOGRAPHIC MATERIAL WHICH COMPRISES AN EMULSION CONTAINING, AS THE DICCONTINUOUS PHASE, A LIGHT-SENSITIVE AQUEOUS GELATINO-SILVER HALIDE EMULSION, AND AS THE CONTINUOUS PHASE A SOLUTION OF A WATER-INSOLUBLE, WATER-PERMEABLE CELLULOSE ETHER IN A WATER-IMMICIBLE ORGANIC SOLVENT. 